What started as a simple picture of a whale’s tail emblazoned on a specialized California license plate decades ago has morphed into one of the most successful environmental programs in the state.

The Whale Tail license plate — celebrating its 20th anniversary — continues to be popular among motorists. Since 1997, 243,000 plates were sold and the program has raised $95 million, according to the California Coastal Commission, the state agency that doles out cash from the Environmental License Plate (ELP) fund.

As expected, on a per capita basis, sales are highest among coast dwellers. Yet the whale plates are surprisingly popular among inland motorists in Southern California, said Chris Parry, the commission’s public education manager.

ZIP code data shows motorists from the San Gabriel Valley, San Bernardino and Riverside counties are among the top purchasers of the specialized license plates in the state, Parry said.

The money is used for the cleanup of beaches, rivers, creeks as well as anti-pollution education programs aimed at school-aged children, she said.